Aside from the fact that it's a remake/reimagining, everything from the gameplay demo looks very good. I think it will at least be as good as Zero Mission. I am curious if you can run/jump and shoot at the same time, however; the gameplay shown didn't make that clear, as they were always using the new 360-aiming feature. Glad that it still includes some of the old songs from MII. Surreal that Mercury Steam is involved...but then, they were trying to pitch stuff in the past. And by the way, I think I heard Dave Cox left to do his own thing similar to Ben Judd.
Now, as for Metroid Prime 4...it sounds like we're looking at more of the same 1st-person adventuring. Other M, for all its faults, opened up some avenues to explore a more expansive 3rd-person 3D adventure...something with the camera system of say, Breath of the Wild. But that doesn't sound like it's happening now. I think they're going to play it safe to try to appease fans. But I'd like to see Metroid move forward, considering there have already been four core 1st-person Metroids and one spinoff. Samus needs to be able to interact with her environment more acrobatically with some new abilities, and can't really do that in 1st person.
All and all, I'm intrigued but disappointed at the same time. Yet, within all that, I do have some hopefulness for the future.